The gene linked to psoriasis was identified by Scientists from Washington University School of Medicine in St. Louis.

Psoriasis was initially thought to be caused by the over reaction of immune system. Later it was found, mutations in CARD 14 gene can lead to plaque psoriasis. It is the common form of psoriasis, which accounts for 80 percent of the cases, are commonly seen as red and white hues of scaly patches appearing on the top layer of the skin.

"We have searched for almost two decades to find a single gene linked to plaque psoriasis." Individually, the rare mutations we have found likely confer a high risk for the disease, and we think they will be important in the search to find new, more effective treatments," said Anne Bowcock, professor of genetics at Washington University School of Medicine in St. Louis and senior author of the study in a university news release.

National Psoriasis Foundation funded the research undertook by Bowcock with co-author Alan Menter, MD, of the Psoriasis Research Institute at the Baylor College of Medicine.

Bowcock and her colleagues used cutting edge DNA technology to unveil a rare mutation in the CARD14 gene in a large family of European descent with a high prevalence of plaque psoriasis and psoriatic arthritis.

The scientists also identified another rare CARD14 mutation in an extended family from Taiwan, who had the condition, which is characterized by dry, raised, red patches covered with silvery scales. Another mutation was identified in a 3-year-old girl, who had severe and rare form of psoriasis, however this case was different, the condition she had was not inherited. It came as a side effect of the treatment for staph infection.

"This is significant because it tells us that CARD14 alone plus an environmental trigger is enough to cause psoriasis," Bowcock explained. "You don't need anything else. This really highlights the importance of finding rare mutations for common diseases like psoriasis."

Researchers were also able to find from the study, another 15 mutations in CARD 14, these mutations were more common in more than 6,000 patients with psoriasis compared to 4,000 healthy controls.

The Researchers showed that mutations in CARD14 can increase the activity of NF-kappaB, a protein that turns on genes. This protein activates certain genes, which releases signaling molecules. These signaling molecules are capable of attracting inflammatory cells to the skin, which results in psoriasis. The study was detailed in the ‘American Journal of Human Genetics.’

“Now, we have a much clearer picture of what is happening in psoriasis,” Bowcock says. “And with all kinds of new therapeutic targets that lie within the CARD14 pathway, the field is wide open.”